Contents
Introduction
The growth of hydrogen production is being driven by its important role in the transition towards cleaner energy and achieving Net Zero targets. When hydrogen is used as an energy source, the main by-product is water vapour, making it an attractive alternative to traditional fossil fuels.
Hydrogen is becoming increasingly important across industries including energy, transport, manufacturing and industrial processes. However, while hydrogen offers significant decarbonisation benefits, its unique physical properties create new challenges when it comes to fire and gas detection, risk management and maintaining safe working environments.
Hydrogen production can generally be divided into two main categories:
Blue Hydrogen
Blue hydrogen is produced from natural gas through a process called steam methane reforming (SMR). This process uses high-temperature steam to separate hydrogen from methane, producing hydrogen alongside carbon dioxide. Carbon capture, utilisation and storage (CCUS) technologies can then be used to capture and store a proportion of the associated carbon emissions.
Green Hydrogen
Green hydrogen is produced through electrolysis, where an electrical current is used to split water (H₂O) into hydrogen and oxygen. When renewable electricity is used to power this process, green hydrogen can be produced with very low associated emissions, making it one of the cleanest methods of hydrogen production.
As hydrogen infrastructure continues to expand, understanding the safety challenges associated with the gas becomes essential. Unlike many traditional fuels, hydrogen behaves differently when released, creating unique challenges for detection systems and risk mitigation.
This blog explores:
- Why hydrogen behaves differently from traditional fuels
- The challenges involved in detecting hydrogen leaks
- Why hydrogen flames create a unique fire detection challenge
- How effective fire and gas detection strategies can improve safety
Why Hydrogen Behaves Differently to Traditional Fuels
Hydrogen has several physical properties that make it different from many conventional fuels. It is the lightest known gas and is significantly less dense than air, meaning it rises rapidly when released into an open environment.
Hydrogen has a very low molecular weight, allowing it to diffuse rapidly and pass through very small openings more readily than many conventional gases. Combined with its low viscosity, this makes leaks more difficult to prevent and highlights the importance of installing suitable detection systems where leaks could occur.
Another challenge is that hydrogen is colourless and odourless, meaning humans cannot identify its presence without specialist detection equipment. This makes reliable gas detection essential for identifying leaks before they develop into a more serious hazard.
Hydrogen flames also create a unique challenge. Unlike many hydrocarbon fires, hydrogen flames can produce limited visible light and may appear pale blue, making them difficult to see, especially in daylight conditions. This makes specialist flame detection technology an important part of protecting personnel and assets.
Hydrogen also has a wide flammability range, with a lower explosive limit (LEL) of approximately 4% and an upper explosive limit (UEL) of around 75% in air. This means that if hydrogen accumulates within this range and an ignition source is present, there is a significant risk of fire or explosion.
Hydrogen has a very low minimum ignition energy (MIE), meaning that a relatively small ignition source can ignite a hydrogen-air mixture under suitable conditions. Potential ignition sources include:
- Static discharge
- Electrical equipment
- Friction
- Hot surfaces
- Open flames
Understanding these characteristics is essential when designing a hydrogen safety system. Detector selection and placement must consider hydrogen’s behaviour to provide the earliest possible warning and reduce risk.
Due to hydrogen’s low density, detector placement must be carefully considered. Locations such as high points within enclosed areas, potential leak sources and areas affected by ventilation patterns should all be assessed as part of the detection strategy.
The Challenge of Detecting Hydrogen Leaks
Why Traditional Floor-Level Gas Detection Can Fail
Traditional gas detection approaches are often designed around the behaviour of heavier gases such as propane, which sink and accumulate at lower levels. As a result, detectors for these gases are commonly positioned closer to floor level.
Hydrogen behaves differently. Due to its low density, it rises quickly when released and can accumulate at higher points within enclosed spaces. A detector positioned only at floor level may not identify a hydrogen leak quickly enough, increasing the potential risk to personnel, equipment and site operations.
For hydrogen applications, detector placement must be based on a detailed risk assessment that considers ventilation, airflow, possible leak points and areas where hydrogen could accumulate.
Where Should Hydrogen Gas Detectors Be Installed
Effective detector placement is one of the most important parts of a hydrogen safety system.
Key considerations include:
- Potential leak sources: Detectors should be positioned near equipment where hydrogen releases could occur, such as storage areas, pipework connections, valves and processing equipment.
- High-level areas: Due to hydrogen’s buoyancy, areas near ceilings and high points should be assessed for possible gas accumulation.
- Ventilation patterns: Air movement can influence how hydrogen disperses, making airflow analysis important when selecting detector locations.
- Dead zones: Areas where gas could collect due to poor ventilation should be identified.
At Protex Systems, our installation approach is supported by specialist 3D mapping software, allowing us to visualise environments and assess detector positioning to help ensure effective coverage.
Hydrogen Flames Create a Unique Fire Detection Problem
Hydrogen fires present a significant detection challenge because they can be difficult to see compared with traditional hydrocarbon fires.
Hydrogen flames produce limited visible light and may appear almost invisible in certain conditions. This means relying on human observation alone is not a suitable method of fire detection.
For combustion to occur, hydrogen requires both oxygen and an ignition source. Potential ignition sources include:
- Static discharge
- Mechanical Impact
- Electrical sources
- Friction
- Thermal heat
- Open flames
Because hydrogen flames can develop rapidly, early detection is essential to minimise risk and protect people, assets and infrastructure.
The Solution to Detecting the Invisible Hydrogen Flame
Ultraviolet/Infrared (UV/IR) flame detectors identify fires by detecting both ultraviolet and infrared radiation produced during combustion. By analysing both wavelengths, they can distinguish genuine flames from many sources of false alarms.
This technology is particularly valuable for hydrogen applications because hydrogen flames can produce very little visible light. Many UV/IR flame detectors are designed to be “solar blind”, allowing them to ignore natural sunlight while responding to radiation associated with active flames.
Fast alarm response times are critical in hydrogen applications, where early detection can help initiate emergency procedures, shutdown systems and protective actions before an incident escalates.
Conclusion: Supporting the Safe Future of Hydrogen Infrastructure
As hydrogen continues to play an increasing role in the transition towards cleaner energy, ensuring the safety of hydrogen facilities will remain a critical priority.
The unique properties of hydrogen mean that effective fire and gas detection requires more than simply adapting traditional approaches. It requires specialist knowledge, careful system design and the correct combination of detection technologies.
Here at Protex, we understand the challenges involved in protecting hydrogen environments and the importance of early, reliable hazard detection. By combining industry expertise with advanced fire and gas detection solutions, we help organisations identify risks, improve site safety and develop protection strategies suited to the demands of hydrogen applications.
As the hydrogen sector continues to grow, robust safety systems will be essential in building confidence and supporting the safe development of future hydrogen infrastructure.
